Device for controlling flow

ABSTRACT

A device for controlling flow, in which device at least part of surfaces coming into contact with flowing gaseous medium, such as air, are coated with a sol-gel coating.

FIELD OF INVENTION

This invention relates to a device for controlling flow, which device is in more detail used for controlling medium, such as air.

BACKGROUND OF INVENTION

A problem of different devices utilised in controlling flow, such as air flow, as of ventilation channels, an exhaust air device (such as e.g. an exhaust air valve or an exhaust register or some other exhaust air device) is dirt accumulating on their surfaces, because the surfaces have not been protected effectively enough against dirt. The accumulation of dirt on the surfaces weakens the usability of the devices and necessitates cleaning the dirt, which causes extra work and costs.

The object of the invention is thus to provide a device for controlling air which device does not get dirty so easily as known devices used for controlling air flow. At the same time, the aim is to provide an easily cleanable device used for controlling air flow.

DESCRIPTION OF INVENTION

The invention is characterised by what is stated in the characterising part of claim 1.

The invention is also characterised by what is stated in enclosed claims 2-9.

According to the inventive idea, at least part of surfaces in the device coming into contact with flowing gaseous medium, such as air, are coated with a sol-gel coating.

By means of the sol-gel technique, it is possible to fabricate of liquid starting materials utilising chemical reactions either a totally or partly inorganic solid network in considerably lower temperatures than conventional ceramic coating technologies. As the name of the technique reveals, it includes forming an inorganic network by means of the gelation of colloidal suspension (sol). By means of the drying and hardening of the gel, it is further possible to form a continuous solid network which can be e.g. a coating. Coatings produced by this technique are thin, typically from hundreds of nanometres to ten micrometres.

By means of the sol-gel chemistry, it is also possible to fabricate inorganic-organic (i.e. ceramic-polymer) composite materials. With these nano-scale composite materials, it is possible to fabricate transparent thin coatings in which it is possible to combine the typical characteristics of different material groups in a molecular scale. By means of these coatings, by adjusting material characteristics, it is possible to affect, inter alia, the dirt resistance, cleanability, self-cleansing, wear resistance and other protective characteristics of the surfaces. The adjustable surface characteristics are, inter alia, surface energy, topography, surface hardness and coating tightness. The sol-gel coatings are often based on silane-based arrangements, but coatings can also be manufactured utilising other alkoxides of metals.

As an advantage compared with earlier organic (e.g. fluoropolymer-based) low surface energy coatings, with coatings produced by sol-gel technique, it is possible to, inter alia, achieve better adhesion of the coating to the base material which, combined with the increase of surface hardness provided by the inorganic sections, leads to end-products with better wear-resistance. An advantage of the sol-gel technique is also that the liquid coating can be applied with different wet-coating methods, which for its part enhances the technical and economic usability of these coatings.

According to the inventive idea, it is possible to coat with the sol-gel coating at least following devices (or parts of apparatuses) used for controlling air:

-   -   a ventilation channel (inlet and outlet channel), such as a         ventilation pipe     -   an exhaust air device (e.g. an exhaust air valve or an exhaust         register or other exhaust air device)     -   an exhaust air blower, especially an extractor fan coupled to an         exhaust air hood     -   an inlet air valve

In the ventilation channel, the coating is formed on the inner surface of the shaft.

In the exhaust air device, the dirt-repellent surface prevents the dirt exiting the room with air from adhering on the surface of the exhaust air device, whereby the product stays cleaner, does not look aesthetically unattractive, its technical specifications remain unchanged, and it requires less frequent cleaning. In the exhaust air blower, the dirt-repellent coating prevents dirt or grease from adhering on the impeller and the shell of the exhaust air blower, whereby technical specifications are kept, the product operates with a good efficiency for whole of its lifetime, there are no balance problems stressing the bearings in the impeller, and it requires less frequent cleaning.

In the inlet air valve, the dirt-repellent coating prevents the dirty air induced from the room from adhering to the surfaces.

The coating has been formed in the above-mentioned devices or their parts by spraying, rolling or spreading.

It is obvious to those skilled in the art that the invention is not limited to the embodiments described above, but it may be varied within the scope of the enclosed claims.

The sol-gel coating used in the invention can also be a hybrid coating or a nano-composite hybrid coating. 

1. A device for controlling flow, in which device at least part of surfaces coming into contact with flowing gaseous medium, such as air, are coated, characterised in that the coating is a sol-gel coating.
 2. A device for controlling flow according to claim 1, characterised in that the device is at least one ventilation pipe.
 3. A device for controlling flow according to claim 1, characterised in that the device is an exhaust air valve.
 4. A device for controlling flow according to claim 1, characterised in that the device is an inlet air valve.
 5. A device for controlling flow according to claim 1, characterised in that the device is an exhaust register.
 6. A device for controlling flow according to claim 1, characterised in that the device is an exhaust air blower.
 7. A device for controlling flow according to claim 1, characterised in that the device is of steel, most advantageously of zinc-coated steel.
 8. A device for controlling flow according to claim 1, characterised in that the coating is a hybrid coating.
 9. A device for controlling flow according to claim 1, characterised in that the coating is a nano-composite hybrid coating.
 10. A device for controlling flow according to claim 2, characterised in that the device is of steel, most advantageously of zinc-coated steel.
 11. A device for controlling flow according to claim 3, characterised in that the device is of steel, most advantageously of zinc-coated steel.
 12. A device for controlling flow according to claim 4, characterised in that the device is of steel, most advantageously of zinc-coated steel.
 13. A device for controlling flow according to claim 5, characterised in that the device is of steel, most advantageously of zinc-coated steel.
 14. A device for controlling flow according to claim 6, characterised in that the device is of steel, most advantageously of zinc-coated steel. 